Programming

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

struct shop
{
        char product[10];
        char code[10];
        int instock;
        float cost;
};

struct shop *magazi;

void fullarray(int start,int end)
{
	int i;
	for ( i=start;i<end;i++ )
  	{
    	printf("-Name of product No %d: ",i+1);
    	scanf("%s",magazi[i].product);
    	printf("\n\tProduct Code : ");
    	scanf("%s",magazi[i].code);
    	printf("\n\tIn stock : ");
    	scanf("%d",&magazi[i].instock);
    	printf("\n\tValue : ");
    	scanf("%f",&magazi[i].cost);
    	printf("\n");
  	}
}

void printproductlist(int pro)
{
	int i;
	printf("|A/A\t|Name\t|Code\t|Stock\t|Cost\n");
	printf("+-------+-------+-------+-------+-------+\n");
  	for(i=0;i<pro;i++)
  	{
    		printf(" %d\t %s\t %s\t %d\t %.2f\n",i+1,magazi[i].product,magazi[i].code,magazi[i].instock,magazi[i].cost);
  	}
}

int main()
{
  	int proionta;
  	printf("Number of products : ");
  	scanf("%d",&proionta);
  
  	magazi=(struct shop *)malloc(proionta*sizeof(struct shop *));
  	if(magazi==NULL)
    		printf("\nMalloc Error");
  
  	fullarray(0,proionta);
  	printproductlist(proionta);
  
  	int proionta2;
  	printf("How many more products? ");
  	scanf("%d",&proionta2);
  
	if(proionta2>0)
  	{
    	magazi=(struct shop *)realloc(magazi,proionta2*sizeof(struct shop *));
    	//realloc memory check
    
    	fullarray(proionta,(proionta2+proionta));
    	printproductlist(proionta+proionta2);
  	}
  
	free(magazi);
  	//scanf("%d",&proionta);
  
  return 0;
}

*** glibc detected *** ./a.out: realloc(): invalid next size: 0x0000000000db4010 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x7a6e6)[0x7fbf5de346e6]
/lib/x86_64-linux-gnu/libc.so.6(+0x7d3e7)[0x7fbf5de373e7]
/lib/x86_64-linux-gnu/libc.so.6(realloc+0xf9)[0x7fbf5de38b39]
./a.out[0x4009d8]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed)[0x7fbf5dddb30d]
./a.out[0x4005c9]

magazi=(struct shop *)realloc(magazi,proionta2*sizeof(struct shop *));

magazi=(struct shop *)realloc(magazi,(proionta+proionta2)*sizeof(struct shop *));

magazi=(struct shop *)malloc(proionta*sizeof(struct shop));